It is well known in the art to manufacture nanocomposites by polymerizing a polyamide monomer while in contact with a layered silicate material, e.g., a sodium smectite clay, that has been treated with a swelling agent, such as an onium ion, to form a nylon polymer-intercalated layered silicate dispersed in additional (non-intercalated) melted polymerized nylon (matrix polymer), e.g., see Toyota U.S. Pat. No. 4,739,007 (RE 37,385). As sown in comparative Example 3 of this Toyota reissue patent, the octadecylamine swelling agent could not provide sufficient clay swelling to produce a nanocomposite sufficient to generate data.
Those skilled in the nanocomposite art have attempted to make a master batch or concentrate that includes a relatively high percentage of nylon-intercalated layered silicate material, e.g., 10% by weight or more layered silicate material, dispersed within a matrix polymer, without success. A primary difficulty in the melt-compounding manufacture of a nylon nanocomposite concentrate is that swelling agent-treated layered silicate materials have excellent compatibility with nylons, leaving little non-intercalated, melted nylon to enable sufficient flow (pumpability) of the composite material out of the compounder. Such concentrates frequently are in a relatively dry chunk or cake form, that adheres to reactor walls and compounder surfaces, having the nylon-intercalated clay unevenly dispersed within the little remaining excess, non-intercalated, nylon matrix polymer. Examples of required low percentages of layered silicate materials used in nylon-intercalated nanocomposite compositions are found in the Toyota U.S. Pat. No. 4,739,007 (RE 37,385) (5%) and Wolf Walsrode U.S. Pat. No. 5,994,445 (2%).